Mercurial > hg > truffle
view agent/src/share/classes/sun/jvm/hotspot/types/TypeDataBase.java @ 7353:b5280041f59e
Experiment with soft alignment for branch targets.
author | Thomas Wuerthinger <thomas.wuerthinger@oracle.com> |
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date | Sun, 13 Jan 2013 19:32:16 +0100 |
parents | f6f3bb0ee072 |
children |
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/* * Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ package sun.jvm.hotspot.types; import java.util.Iterator; import sun.jvm.hotspot.debugger.Address; public interface TypeDataBase { /** Equivalent to lookupType(cTypeName, true) */ public Type lookupType(String cTypeName); /** For simplicity of the initial implementation, this is not guaranteed to work for primitive types. If throwException is true, throws an (unspecified) run-time exception if the type is not found. */ public Type lookupType(String cTypeName, boolean throwException); /** Equivalent to lookupIntConstant(constantName, true) */ public Integer lookupIntConstant(String constantName); /* For convenience, this interface also encapsulates the fetching of integer constants, i.e., enums. If no constant of this name was present, either throws an (unspecified) run-time exception or returns null. */ public Integer lookupIntConstant(String constantName, boolean throwException); /** Equivalent to lookupLongConstant(constantName, true) */ public Long lookupLongConstant(String constantName); /* For convenience, this interface also encapsulates the fetching of long constants (those requiring 64 bits on 64-bit platforms). If no constant of this name was present, either throws an (unspecified) run-time exception or returns null. */ public Long lookupLongConstant(String constantName, boolean throwException); /** Accessors for types representing the Java primitive types; used for both proper type checking and for walking down Java arrays. */ public Type getJBooleanType(); public Type getJByteType(); public Type getJCharType(); public Type getJDoubleType(); public Type getJFloatType(); public Type getJIntType(); public Type getJLongType(); public Type getJShortType(); /** Returns the size of a C address in bytes. This is currently needed in order to properly traverse an array of pointers. Traversing an array of structs, for example, is possible by looking up the type of the struct and multiplying the index by its size when indexing off of a base Address. (FIXME: what about alignment?) */ public long getAddressSize(); /** Returns the size of an oop in bytes. This is currently needed in order to properly traverse an array of oops; it is distinguished from the address size, above, because object pointers could conceivably have a different representation than direct pointers. Traversing an array of structs, for example, is possible by looking up the type of the struct and multiplying the index by its size when indexing off of a base Address. */ public long getOopSize(); /** <P> This is an experimental interface emulating C++'s run-time type information (RTTI) mechanism: determines whether the given address is a pointer to the start of a C++ object of precisely the given type -- it does not search superclasses of the type. The convention is that this returns false for the null pointer. It is needed to allow wrapper Java objects of the appropriate type to be constructed for existing C++ objects of polymorphic type. This method is only intended to work for C++ types (implying that we should rename this package and the classes contained within back to "ctypes"). Further, since the vptr offset in an object is known at compile time but not necessarily at runtime (unless debugging information is available), it is reasonable for an implementation of this method to search nearby memory for the (known) vtbl value for the given type. For this reason, this method is not intended to support scans through memory finding C++ objects, but is instead targeted towards discovering the true type of a pointer assumed to be intact. </P> <P> The reason this method was placed in the type database is that the latter is the first level at which it could be exposed, and placing it here could avoid modifying the Type interface. It is unclear what other, if any, vtbl access would be useful (or implementable), so we are trying to avoid changing interfaces at this point to support this kind of functionality. </P> <P> This method necessarily does not support multiple inheritance. </P> */ public boolean addressTypeIsEqualToType(Address addr, Type type); /** Helper routine for guessing the most derived type of a polymorphic C++ object. Iterates the type database calling addressTypeIsEqualToType for all known types. Returns a matching Type for the given address if one was found, or null if none was found. */ public Type guessTypeForAddress(Address addr); /** Helper routine for guessing the most derived type of a polymorphic C++ object. Requires a baseType that must be virtual so that lookup can be performed without false positives */ public Type findDynamicTypeForAddress(Address addr, Type baseType); /** Returns an Iterator over the Types in the database. */ public Iterator getTypes(); /** Returns an Iterator over the String names of the integer constants in the database. */ public Iterator getIntConstants(); /** Returns an Iterator over the String names of the long constants in the database. */ public Iterator getLongConstants(); }